Method for identifying compounds modulating taste transduction

Abstract

The invention provides isolated nucleic acid and amino acid sequences of taste cell specific G-protein coupled receptors, antibodies to such receptors, methods of detecting such nucleic acids and receptors, and methods of screening for modulators of taste cell specific G-protein coupled receptors.

1. A method for identifying a compound that modulates taste signaling in taste cells, the method comprising the steps of:
 (i) contacting the compound with a taste transduction G-protein coupled receptor polypeptide, wherein the polypeptide is expressed in a taste cell and binds a bitter tastant, the polypeptide comprising greater than about 95% amino acid sequence identity to SEQ ID NO:41; and 
 (ii) determining a functional effect of the compound upon the polypeptide, thereby identifying a compound that modulates taste signaling in taste cells. 
 
     
     
       2. The method of  claim 1 , wherein the polypeptide has G-protein coupled receptor activity. 
     
     
       3. The method of  claim 1 , wherein the functional effect is determined by measuring changes in intracellular cAMP, cGMP, IP3, or Ca 2+ . 
     
     
       4. The method of  claim 1 , wherein the functional effect is a chemical effect. 
     
     
       5. The method of  claim 1 , wherein the functional effect is a physical effect. 
     
     
       6. The method of  claim 1 , wherein the functional effect is determined by measuring binding of the compound to an extracellular domain of the polypeptide. 
     
     
       7. The method of  claim 1 , wherein the functional effect is determined by measuring binding of radiolabeled GTP to the polypeptide. 
     
     
       8. The method of  claim 1 , wherein the polypeptide is recombinant. 
     
     
       9. The method of  claim 1 , wherein the polypeptide is from a rat, a mouse, or a human. 
     
     
       10. The method of  claim 1 , wherein the polypeptide is expressed in a cell or cell membrane. 
     
     
       11. The method of  claim 10 , wherein the functional effect is measured by determining changes in the electrical activity of cells expressing the polypeptides. 
     
     
       12. The method of  claim 10 , wherein the cell is a eukaryotic cell. 
     
     
       13. The method of  claim 1 , wherein the polypeptide comprises SEQ ID NO:41. 
     
     
       14. The method of  claim 1 , wherein the bitter tastant is 6-n-propylthiouracil, sucrose octaacetate, raffinose undecaacetate, cycloheximide, or quinine.